JKP505
I don’t think if you look at the airports master plan that a new terminal is planned at this stage. An extension from the existing one to a new pier may be.
As for criticising the old part of the terminal, well the only people who seem to do that are the spotters!
The people who travel through it don’t seem to mind. Once you’ve checked in these days it’s off through to the massively enlarged and very nice departure lounge!